For disc-shaped recording media, such as compact discs (CDs) and digital versatile disks (DVDs), measures have been taken to protect productions, such as content, by preventing content recorded on such recording media from being illegally copied. Compact discs with copy protection will be sold.
However, since content of compact discs without copy protection is easily copied, copied CD-Rs and CD-RWs are distributed. It is obvious that illegal copying by evasion of copy protection exists. In this case, such copied discs will also come into circulation.
Since no measures are taken for copy protection for copied discs, copying of a copied disc (CD-R, CD-RW, or the like) to another disc (CD-R, CR-RW, or the like) is permitted without any restriction. Such copying may reach beyond personal use, and this is also unwanted in view of protecting copyright holders.
In addition to the recording media mentioned above, DVD-Rs, DVD-RWs, and the like are viewed as disc-shaped recording media that can be copied and that may need copy protection.
The present invention solves the known problems described above and proposes, in particular, a writable recording medium, an information recording method, an information playback method, an information recording apparatus, and an information playback apparatus that record copy-protectable information on the writable recording medium and that determine the recording medium to be a copied recording medium when the information is not satisfied when playing back the recording medium.